Alert systems and methods for a vehicle

ABSTRACT

Methods and vehicles are provided for providing haptic feedback to a vehicle occupant. In one embodiment, the method includes determining at least one of interior conditions and exterior conditions of a vehicle. The vehicle includes a plurality of haptic actuators disposed in a seat. The method further includes calculating at least one of a pulse width modulation (PWM) pattern and an on/off compensation pattern based on the determined interior conditions and exterior conditions. The method further includes generating a signal with active periods that include at least one of the calculated patterns to command the plurality of haptic actuators to produce haptic pulses.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.61/663,516 filed Jun. 22, 2012 and hereby incorporated by reference.

TECHNICAL FIELD

The technical field generally relates to driver alert systems andmethods, and more particularly relates to control systems and methodsfor haptic devices associated with a vehicle seat assembly.

BACKGROUND

Collision avoidance systems warn drivers of potential collision threatsthat may be in the line-of-sight of the driver (e.g., detected byon-board vehicle sensors) or out of the line-of-sight of the driver(e.g., determined from wireless vehicle-to-vehicle communications,vehicle-to-infrastructure communications, and/or vehicle-to-pedestriancommunications). Collision avoidance systems may generate visual and/orauditory alerts to warn a vehicle driver of the potential collisionthreats. These typical collision avoidance systems for alerting thedriver to a condition that needs attention may be distracting andconfusing. Such distraction and confusion might have the potential toincrease driver response time and decrease effectiveness of thecollision avoidance system.

Accordingly, it is desirable to provide methods and systems for alertinga driver of the vehicle using a haptic device, particularly improvedmethods and systems that generate more effective haptic alerts. Otherdesirable features and characteristics of the present invention willbecome apparent from the subsequent detailed description and theappended claims, taken in conjunction with the accompanying drawings andthe foregoing technical field and background.

SUMMARY

A method is provided for alerting an occupant of a vehicle. In oneembodiment, the method includes determining at least one of interiorconditions and exterior conditions of a vehicle. The vehicle includes aplurality of haptic actuators disposed in a seat. The method furtherincludes calculating at least one of a pulse width modulation (PWM)pattern and an on/off compensation pattern based on the determinedinterior conditions and exterior conditions. The method further includesgenerating a signal with active periods that include at least one of thecalculated patterns to command the plurality of haptic actuators toproduce haptic pulses.

A method is provided for alerting an occupant of a vehicle. In oneembodiment, the method includes determining at least one of interiorconditions and exterior conditions of a vehicle. The vehicle includes aplurality of haptic actuators disposed in a seat. The method furtherincludes determining a high frequency component of haptic pulses tocommand from the haptic actuators based on the interior conditionsand/or the exterior conditions. The method further includes calculatingat least one of a pulse width modulation (PWM) pattern and an on/offcompensation pattern based on the interior conditions and/or theexterior conditions to actuate the plurality of haptic actuators andgenerate haptic pulses with the high frequency component. The methodfurther includes generating a signal with active periods that include atleast one of the calculated patterns to command the plurality of hapticactuators to produce the haptic pulses.

A vehicle is provided for providing haptic feedback to an occupant. Inone embodiment, the vehicle includes a seat for supporting a driver ofthe vehicle, a plurality of haptic actuators disposed in the seat andconfigured to produce haptic pulses, and a controller. The controllerdetermines interior conditions and/or exterior conditions of thevehicle, calculates a pulse width modulation (PWM) pattern and/or anon/off compensation pattern based on the interior conditions and/or theexterior conditions, and generates a signal with active periods thatinclude at least one of the calculated patterns to command the pluralityof haptic actuators to produce the haptic pulses.

DESCRIPTION OF THE DRAWINGS

The exemplary embodiments will hereinafter be described in conjunctionwith the following drawing figures, wherein like numerals denote likeelements, and wherein:

FIG. 1 is a functional block diagram illustrating a vehicle thatincludes a driver alert system in accordance with exemplary embodiments;

FIG. 2 is a schematic side positional view of a vehicle seat assembly ofthe vehicle of FIG. 1 in accordance with exemplary embodiments;

FIG. 3 is a partial top positional view of the seat assembly of FIG. 2in accordance with exemplary embodiments;

FIG. 4 is a side positional view of a motor incorporated into the seatassembly of FIG. 3 in accordance with exemplary embodiments;

FIG. 5 is a graphical view of an actuation profile and an accelerationprofile in accordance with exemplary embodiments; and

FIGS. 6-8 are flowcharts illustrating alert methods that may beperformed by the alert systems in accordance with exemplary embodiments.

DETAILED DESCRIPTION

The following detailed description is merely exemplary in nature and isnot intended to limit the application and uses. Furthermore, there is nointention to be bound by any expressed or implied theory presented inthe preceding technical field, background, brief summary or thefollowing detailed description. It should be understood that throughoutthe drawings, corresponding reference numerals indicate like orcorresponding parts and features. As used herein, the term module refersto an application specific integrated circuit (ASIC), an electroniccircuit, a processor (shared, dedicated, or group) and memory thatexecutes one or more software or firmware programs, a combinationallogic circuit, and/or other suitable components that provide thedescribed functionality.

Broadly, exemplary embodiments discussed herein refer to driver alertsystems and methods implemented as a vehicle seat assembly. The driveralert systems and methods may include actuators incorporated into seatbolsters that provide improved haptic responses and more efficientinstallation.

FIG. 1 is a functional block diagram illustrating a vehicle 10 thatincludes a driver alert system 100 in accordance with exemplaryembodiments. Although not shown, the vehicle has a generally knownconfiguration with one or more seats for supporting a driver and abattery 12 for supplying a voltage to components of the vehicle 10.Additional details about a vehicle seat assembly 200 will be providedbelow after a brief description of the driver alert system 100.

In general, the driver alert system 100 includes one or more collisionavoidance modules 110, a communications module 120, a control module130, a haptic alert assembly (or haptic feedback assembly) 140, and oneor more additional alert devices, including a visual alert device 150,an auditory alert device 152, and an infotainment alert device 154. Asintroduced above and as described in greater detail below, the hapticalert assembly 140 may be incorporated into the vehicle seat assembly200, which may also be considered part of the driver alert system 100.During operation and as also discussed in greater detail below, thecontrol module 130 receives input signals from the collision avoidancemodules 110 and communications module 120 that indicate the possibilityof a collision condition. The control module 130 evaluates the inputsignals, and as appropriate, operates the haptic alert assembly 140and/or alert devices 150, 152, 154 to alert the driver of the collisioncondition. As such, the driver alert system 100 may function to alertthe driver of a collision condition such that crash avoidance maneuvers(e.g., braking and/or steering) and/or crash mitigation responses (e.g.,braking and/or steering) may be initiated. Although the figures shownherein depict example arrangements of elements, additional interveningelements, devices, features, or components may be present in someembodiments.

In general, the collision avoidance modules 110 include one or moreon-board vehicle sensors (e.g., camera, radar, and/or lidar) that detecta potential for a collision information based on the vehicle sensorsignals. The collision avoidance modules 110 may generally beimplemented as, for example, forward collision warning systems, lanedeparture warning or lane keeping assist systems, front park assistsystems, rear park assist systems, front and rear automatic brakingsystems, rear cross traffic alert systems, adaptive cruise control (ACC)systems, side blind zone (or spot) detection systems, lane change alertsystems, driver attention systems (e.g., distraction- and/ordrowsiness-monitoring), and front pedestrian detection systems and rearpedestrian detection systems. As noted above, the driver alert system100 may further include communications module 120 to enablecommunications between vehicles, between the vehicle and aninfrastructure, and/or between the vehicle and pedestrians/cyclists toforecast potential collisions due to traffic, pedestrian, bicycles, oractivity either inside the line-of-sight of the driver or outside of theline-of-sight of the driver (e.g., a road hazard or traffic jam ahead isdetected beyond the driver's line-of-sight). In general, the collisionavoidance modules 110 and/or communications module 120 arecommunicatively coupled to a control module 130 that evaluates apotential for a collision based on the vehicle sensor signals and/orcommunications.

The control module 130 includes one or more submodules or units 132,134, 136, and 138 that cooperate to evaluate the signals from thecollision avoidance modules 110 and communications module 120, and inresponse, generate a control signal for operating one or more of thehaptic alert assembly 140 and/or the devices 150, 152, 154. As describedbelow, the control module 130 may include a monitoring unit 132, a userconfiguration unit 134, an evaluation unit 136, and a patterndetermination unit 138. As can be appreciated, the units shown in FIG. 1may be integrated with other control modules or may be implementedseparately for each collision avoidance system. The control module mayalso be a plug-in device that is installed into the onboard diagnosticsconnector of the vehicle (OBD-II), a retrofit module that is collocatedwith an existing vehicle module (i.e., installed at the host moduleusing an adaptation connector), or as a replacement part for an existingvehicle system (i.e., inside rear-view mirror assembly). The controlmodule may also be a wireless device that is communicatively coupled tothe vehicle over a short range wireless connection such as Wi-Fi,Bluetooth, NFC or similar.

In general, the monitoring unit 132 monitors input from variouscomponents of the vehicle 10, particularly the haptic alert assembly 140to determine proper operation. If the monitoring unit 132 determinesthat a component is malfunctioning, the monitoring unit 132 may generatea warning message, a warning signal, and/or a faulty condition statusthat may be communicated to the vehicle driver or technician.

The user configuration unit 134 manages the display of a configurationmenu and manages user input received from a user interacting with theconfiguration menu. Such a configuration menu may be displayed on adisplay device within the vehicle or remote from the vehicle. In variousembodiments, the configuration menu includes selectable options that,when selected, allow a user to configure the various alert settingsassociated with the devices 150, 152, 154 and/or haptic alert assembly140. The alert settings for the haptic alert assembly 140 may include,but are not limited to, an occurrence of the vibration (e.g., whether ornot to perform the vibration for a particular mode), a location of thevibration on the seat, an intensity of the vibration, a duration of thevibration, a rate of the vibration, and/or a frequency of the pulses ofthe vibration. Based on the user input received from the userinteracting with the configuration menu, the user configuration unit 134stores the user configured alert settings in an alert settings database.As can be appreciated, the alert settings database may include volatilememory that temporarily stores the settings, non-volatile memory thatstores the settings across key cycles, or a combination of volatile andnon-volatile memory.

The evaluation unit 136 functions to ascertain the current mode of thevehicle 10 and to evaluate, based on that mode, the condition inputsignals and communications from the collision avoidance modules 110 andcommunications module 120. Based on this evaluation, the evaluation unit136 may determine that a collision condition exists, e.g., that thevehicle may have the potential to be in a collision. Upon declaring acollision condition, the evaluation unit 136 sends an appropriate signalto the pattern determination unit 138. The signal may also indicate thenature of the collision condition.

Upon indication of the collision condition, the pattern determinationunit 138 generates a control signal to operate one or more of thedevices 150, 152, 154 and/or haptic alert assembly 140. In one exemplaryembodiment, the control signal may define one or more alert patternsbased on the collision condition. The alert patterns include hapticalert patterns, visual alert patterns, and/or auditory alert patterns.In various embodiments, the pattern determination unit 138 determinesthe alert patterns by retrieving the predefined alert settings and/orthe user defined alert settings from the alert setting database based onthe collision condition. Additional details about the alert patterns arediscussed below.

The alert pattern may also indicate a synchronization of multipleaspects of the devices 150, 152, 154 and haptic alert assembly 140. Forexample, the haptic alert assembly 140 may include multiple actuators,such as right and left actuators as discussed below. As such, the alertpattern may include directional commands, such as the operation of theright or left actuator to provide additional information about thenature of the collision condition (e.g., location of the crash threat).

Any suitable visual alert device 150 and auditory alert device 152 maybe provided. As example, the visual alert device 150 may be implementedas a light within the interior of the vehicle 10 and the auditory alertdevice 152 may be implemented as part of the vehicle stereo system. Theinfotainment alert device 154 may correspond to a device or combinationof devices for interacting with the vehicle 10. For example, theinfotainment alert device 154 may include a display screen integrated inthe dashboard and user interfaces, such as a touch screen, buttons,and/or rotary dials. The alert signals associated with the infotainmentalert device 154 may take the form of visual, audible, and/or hapticalert signals (e.g., touch screen haptic pulses felt by the finger whenpressing an area of the touch screen).

The haptic alert assembly 140 may be any suitable haptic alert device.In one exemplary embodiment, the haptic alert assembly 140 isimplemented as part of the vehicle seat assembly 200, as will now bedescribed in greater detail.

FIG. 2 is a schematic side view of a vehicle seat assembly 200 inaccordance with an exemplary embodiment. The seat assembly 200 may beinstalled on a floor of the passenger area of a vehicle, such as thevehicle 10 described above. In one exemplary embodiment, the seatassembly 200 is a driver seat for an automobile, although in otherexemplary embodiments, the seat assembly 200 may be a passenger seatand/or implemented into any type of vehicle.

As shown in FIG. 2, the seat assembly 200 includes a lower seat member210, a seat back member 220, a head rest 230, and a haptic alertassembly 140, such as the haptic alert assembly 140 introduced above inthe discussion of FIG. 1. The lower seat member 210 defines a generallyhorizontal surface for supporting an occupant (not shown). The seat backmember 220 may be pivotally coupled to the lower seat member 210 anddefines a generally vertical surface for supporting the back of anoccupant. The head rest 230 is operatively coupled to the seat backmember 220 to support the head of an occupant. Although not shown, thelower seat member 210, the seat back member 220, and the head rest 230are each formed by a foam body mounted on a frame and covered with acover.

As described in greater detail below, the haptic alert assembly 140 isinstalled in the lower seat member 210 to provide haptic signals (e.g.,vibrations) to the occupant in predetermined situations. As noted above,the haptic alert assembly 140 is part of the driver alert system 100 toalert the driver and/or automatically control (e.g., brake, or steer)the vehicle to either help the driver avoid the crash or reduce thecrash impact speed.

FIG. 3 is a top view of the seat assembly 200 of FIG. 2 in accordancewith an exemplary embodiment. As shown in FIG. 3, the lower seat member210 generally includes a seat pan 310, a first bolster 320, and a secondbolster 330. The bolsters 320, 330 are generally considered the leftoutermost and right outermost side of the lower seat member 210,respectively. As can be appreciated, in various other embodiments, theseat pan 310 can be without bolsters 320, 330, such as a flat seat. InFIG. 3, the bolsters 320, 330 are arranged on the longitudinal sides ofthe seat pan 310 (e.g., the left and right sides) to support the legsand thighs of the occupants. Each of the bolsters 320, 330 may beconsidered to have a front end 324, 334 and a back end 326, 336 relativeto the primary direction of forward travel. As shown, the seat backmember 220 may overlap a portion of the bolsters 320, 330 at the backends 326, 336. As is generally recognized in seat design, the bolsters320, 330 are arranged on the sides of the lower seat member 210,typically at an angle to the seat pan 310.

FIG. 3 additionally illustrates positional aspects of the haptic alertassembly 140. In particular, the haptic alert assembly 140 includes afirst actuator 322 installed in the first bolster 320 and a secondactuator 332 installed in the second bolster 330. The first and secondactuators 322, 332 are coupled to a haptic controller 350 with a wiringharness 360. In one exemplary embodiment, the haptic controller 350corresponds to the control module 130 discussed above, although thehaptic controller 350 may alternatively be a separate controller. As canbe appreciated, the controller 350 may be integrated with other controlmodules or may be implemented separately for each collision avoidancesystem. The controller may also be a plug-in device that is installedinto the onboard diagnostics connector of the vehicle (OBD-II), aretrofit module that is collocated with an existing vehicle module(i.e., installed at the host module using an adaptation connector), oras a replacement part for an existing vehicle system (i.e., insiderear-view mirror assembly). The controller may also be a wireless devicethat is communicatively coupled to the vehicle over a short rangewireless connection such as Wi-Fi, Bluetooth, NFC or similar.

In general, the first and second actuators 322, 332 are positioned toenable the occupant to clearly and quickly perceive and differentiatevarious types of haptic signals without negatively impacting seatcomfort and seat durability. The particular locations of the first andsecond actuators 322, 332 may additionally depend on seat designconsiderations, including seat structure, bolster design, and foamthickness. Although the first and second actuators 322, 332 aredescribed as being positioned in the bolsters 320, 330, in otherembodiments, the first and second actuators 322, 332 may be positionedin other areas of the seat assembly 200, such as the seat pan 310, seatback member 220, and/or the head rest 230.

As shown, first and second actuators 322, 332 (e.g., two actuators) areprovided to independently generate the desired haptic signals to theoccupant either on the left side, right side, or both the left and rightsides. However, in other embodiments, additional actuators may beprovided. In one exemplary embodiment, installation of the first andsecond actuators 322, 332 in the first and second bolsters 320, 330functions to isolate the actuators' vibration from one another such thatthe actuators 322, 332 tactile vibrations are decoupled (or isolated)from one another. As such, the vibrations may be highly localized.Consequently, when it is desired to generate only one of these twoactuators (e.g., the left actuator), the seat occupant does notexperience unintended vibrations that can travel through the seatcushion material or seat structure to the other actuator location (e.g.,the right actuator). As one example, the peak amplitude of measuredvertical acceleration at the activated actuator location normal to theseat bolster surface may be at least seven times greater than the peakamplitude of the measured acceleration along the axis parallel to theaxis of rotation of the motor actuation.

In one exemplary embodiment, the first and second actuators 322, 332 arepositioned about two-thirds of the distance between the front ends 324,334 of the bolsters 320, 330 and the seat back member 220. In oneexemplary embodiment, the first and second actuators 322, 332 (e.g., theforward edge of the actuators 322, 332) may be laterally aligned withthe H-point (or hip-point) 370, as schematically shown. In otherembodiments, the actuators 322, 332 (e.g., the rear edge of theactuators 322, 332) are positioned approximately 25 cm forward of theH-point 370 and/or between 0 cm and 25 cm forward of the H-point 370. Asgenerally recognized in vehicle design, the H-point 370 is thetheoretical, relative location of an occupant's hip, specifically thepivot point between the torso and upper leg portions of the body. Ingeneral and as discussed above, the actuators 322, 332 are positionedwith consideration for performance, seat durability, and seat comfort.However, the exemplary positions discussed herein enable advantageousoccupant reaction times from the perspectives of both recognition andinterpretation (e.g., feeling the vibration and recognizing the alertdirection), typically on the order of hundreds of milliseconds. In oneexemplary embodiment, the location of the H-point 370 is unchanged ascompared to a lower seat member without a haptic feedback assembly.

As described below, the two actuators 322, 332 provide advantages withrespect to the occupant detection and interpretation of alert (e.g., thedirection of the crash threat), seat comfort, and seat durability. Inone exemplary embodiment, the actuators 322, 332 may individuallygenerate first and second portions of a haptic alert, respectively, orbe individually operated to generate the entire response. As an example,the two actuators 322, 332 provide a clear signal regarding the natureof the alert and direction the alert is referring to, e.g., rapidpulsing of the left actuator 322 signals to the driver they have driftedacross a left lane marking without their left turn signal activated,similar to a rumble strip warning. Additional actuators, such as alsoactivating the right actuator in this case of a left lane departure,will reduce the chance the occupant will correctly associate theactivation with a left side event and it will increase the time it takesfor the occupant to determine a left side event has occurred (e.g., ifthe actuation occurs when the driver is looking away from the roadahead). Similarly, the position and size of the actuators 322, 332provide advantages with respect to seat durability, which can bemeasured by commonly used sliding entry, jounce and squirm, and kneeload durability seat validation tests. The actuators 322, 332 may bedesigned to function for 100,000 actuation sequences over 150,000 milesof vehicle life. Other positions may compromise occupant detection andalert effectiveness, seat comfort, and seat durability. For example, ifthe haptic device is placed at the very front edge of the seat, theoccupant may not perceive seat vibrations if they pull their legs backagainst the front portions of the seat.

FIG. 4 is a side view of a motor 400 that may be incorporated into theactuators 322, 332 described above. As an example, one motor 400 may beincorporated into each actuator 322, 332. The motor 400 may be arelatively small and light motor, for example, a 12 VDC motor in whichan electric current drives magnets or coils to rotate an output shaft402. An eccentric mass 404 is coupled to and rotates with the shaft 402to produce a haptic response. In other words, the eccentric mass 404 isselectively rotated to produce a vibrating sensation for an occupant.The motor 400 and/or shaft 402 may be sized and shaped to produce thedesired characteristics of the haptic response. Other types of motorsand/or actuation assemblies may be provided, including smart materials.

As noted above, the haptic controller 350 may have various predeterminedpatterns implemented with active and inactive periods of operation.During the active period, the haptic controller 350 commands theselected motor 400 (e.g., the motor in actuator 322 or the motor 400 inactuator 332) to rotate, and during the inactive period, the hapticcontroller 350 does not commands the selected motor 400 to rotate.

The motor 400 may be operated in a manner to create haptic pulses at thesurface of the seat bolster (e.g., bolster 320, 330) varied in length,spacing, and intensity to create the haptic feedback felt by the driverof the vehicle. The haptic feedback created by the haptic pulses, inconjunction with the location of the vibration pulses, indicates thetype of alert, e.g., the nature of the collision condition. The hapticcontroller 350 determines the appropriate voltage and determines, forexample, a pulse width modulation (PWM) pattern of “on” periods wherevoltage is provided to the motor 400 and “off” periods where no voltageis provided to the motor 400.

Referring now to FIG. 5, examples of an actuation profile 500 and anacceleration profile 510 are illustrated in accordance with someembodiments. The actuation profile 500 represents the commandedactuation signal sent to the motors to determine the intensity andduration of haptic feedback felt by the driver. For example, theactuation profile may represent the average signal generated by thehaptic controller 350 to command the actuators 322, 332. The actuationprofile 500 includes an active period 502 and an inactive period 504.For example, the active period 502 may be defined by a positive voltagesignal generated by the haptic controller 350 and the inactive period504 may correspond to a low or zero voltage signal generated by thehaptic controller 350. Each active period 502 has a leading edge 506 anda trailing edge 508. In some embodiments, the leading edge 506 and/orthe trailing edge 508 may include a taper 509 to adjust the accelerationprofile of the haptic pulse, as will be described below. During theactive period 502, the haptic actuator is commanding the selected motorsto rotate. During the inactive period 504, the haptic actuator is notcommanding the selected motors to rotate. It should be appreciated thatthe active period 502 is a representation of the average signal appliedto the motors, and in fact may include rapidly repeating PWM sequences.

The acceleration profile 510 indicates the acceleration at the surfaceof the seat bolster. For example, the acceleration profile 510 may bemeasured with an accelerometer placed at the surface of the firstbolster 320 to measure acceleration due to actuation of the actuator322. The acceleration profile 510 illustrates haptic pulses 512 that arevaried in length and spacing to create the haptic feedback felt by thedriver of the vehicle. The haptic feedback created by the haptic pulses512 indicates the type of alert. The acceleration profile 510 includesfirst direction data 514, second direction data 516, and third directiondata 518. In the embodiment illustrated, the first direction data 514corresponds to acceleration measured normal to the seat bolster surface,the second direction data 516 corresponds to acceleration measured atthe surface of the bolster in a fore-aft direction with respect to themotor, and the third direction data 518 corresponds to accelerationmeasured at the surface of the bolster in a lateral directionperpendicular to the vertical and fore-aft directions.

In one exemplary embodiment, the peak amplitude of measured verticalacceleration at the activated actuator location normal to the seatbolster surface is at least five times greater than the peak amplitudeof the measured acceleration in the vertical, fore-aft, and lateraldirections at non-activated actuator locations. Moreover, by way ofexample, the actuation profile may be adjusted to create a desiredacceleration profile felt by variously sized drivers. For example, ahigh frequency component of the vibration corresponding to therotational speed of the motor 400 may be within the range of 55 to 67Hz. The high frequency component is also selected to reduce undesirableinteractions with road vibration frequencies. The vertical accelerationof the vibration may be between 50 and 72 m/s2. In one example, thevertical acceleration level is within 10% across each of the actuatorlocations.

In general, the acceleration profile 510 at the seat bolster increasesduring the active period 502 of the actuation profile 500 and decreasesduring the inactive period 504 of the actuation profile 500. Therelative duration of the active period 502 and inactive period 504 ofthe actuation profile 500 may be used to indicate the severity of thepotential hazard. Additionally, the time between active periods 502 andinactive periods 504 may be decreased to indicate more urgent alerts.For example, unique haptic alert actuation profiles 500 may be used todistinguish between near-field imminent crash alerts and far-fieldadvisory events that may occur beyond the driver's line of sight.

Referring now to FIG. 6, a flowchart for a method 600 of controlling ahaptic system is illustrated in accordance with some embodiments. Ingeneral, the method 600 establishes mapping of system alerts tovibration motors, establishes a number of vibration pulses to command,and establishes on/off cycle repeating patterns of pulses. In theexample provided, the operations of the method 600 are performed by thehaptic controller 350. As can be appreciated in light of the disclosure,the order of operation within the method is not limited to thesequential execution as illustrated in FIG. 6, but may be performed inone or more varying orders as applicable and in accordance with thepresent disclosure. In various embodiments, the method can be scheduledto run based on predetermined events, and/or can run continually duringoperation of the vehicle.

In a first operation 602, a controller evaluates conditions related tothe vehicle. The conditions may include conditions of the environmentsurrounding and within the vehicle. For example, the haptic controller350 may evaluate data from the sensors (e.g., camera, radar, and/orlidar) of the collision avoidance modules 110.

The haptic controller 350 determines whether to command a haptic alertbased on the conditions. For example, the haptic controller 350 maydetermine whether the conditions indicate a potential collision (e.g.,in tight spaces when parking, high speed collision with an approachingvehicle while driving, etc.). If the controller 350 determines not tocommand a haptic alert, then the controller returns to operation 602 tocontinue evaluating the conditions. If the control module determines tocommand the haptic alert, then the controller performs operation 606.

In operation 606, the controller determines what type of haptic alert tocommand based on the conditions evaluated in operation 602. For example,the haptic alert may indicate a Lane Departure Warning, a Lane keepingAssist, a Rear Cross Traffic Alert, a Forward Collision Alert, aCollision Imminent Braking, an Adaptive Cruise Control event, a RearPark Assist, a Back-Up Warning, a Front Pedestrian Detection, a RearPedestrian Detection event, or other types of events.

The controller determines a pattern of which haptic actuators to commandin operation 608 based on the type of haptic alert and the location ofthe haptic actuators. For example, the controller 350 may command thefirst actuator 322, the second actuator 332, or both actuators based onthe type of haptic alert indicated. In one example, the second actuator332 positioned near the driver's right leg is selected for actuationwhen an object is detected approaching from the right side of thevehicle 10 while the driver is backing up. Conversely, when an object isdetected approaching from the left side of the vehicle 10 while thedriver is backing up, the first actuator 322 positioned near thedriver's left leg is selected for actuation. The actuators are similarlyselected for right and left lane departure warnings, or other potentialhazards detected to the sides of the vehicle.

When a potential hazard is detected to the front or rear of the vehicle,the haptic controller 350 may select the actuators 322, 332 located onboth sides of the driver. Motor selection patterns may be used toindicate various alerts. For example, where multiple motors are locatedin a particular region, the motors may be selected simultaneously or maybe alternated in any pattern. For example, the motors may be alternatelyactuated to create zigzag or circular patterns.

In operation 610, the controller selects the number of active hapticperiods to command based on the type of haptic alert. As indicatedabove, the active periods correspond to haptic pulses transmitted to thedriver through the seat. Fewer active periods and pulses may indicate aless severe alert, while greater numbers of active periods and pulsesmay indicate a more severe alert. For example, five pulses may indicatean imminent crash alert to a vehicle directly head, whereas two pulsesmay indicate a far-field forward traffic event (e.g., traffic jamahead).

In operation 612, the controller selects the duration of the activehaptic periods and inactive haptic periods based on the type of hapticalert. By selecting the durations, the length and time between pulsesmay be adjusted. For example, a park assist application may useseparation time between pulses or the number of pulses to indicateproximity of the vehicle to objects. Separation between pulses may beincreased by increasing the duration of the inactive periods. When anobject is first detected, one pulse, two pulses, or a unique pulsesignature may be provided. As the vehicle moves closer to the object,the separation time between pulses (or pulse signatures) is decreaseduntil a minimum separation time is reached and/or the number of pulsescan be increased (e.g., five pulses can be triggered). The intensitysettings for the proximity alerts may be distinct from the crash alertsettings to reduce customer discomfort or annoyance.

In another example, alert cadence between systems may be quickly toggledto indicate a multiple scenario event. For example, if there is aforward event that is concurrent with a side event, the time betweenactive periods 502 and inactive periods 504 of the actuation profile 500may be decreased to indicate the multiple alert states. For example,instead of alternating forward-side-forward-side alerts at 100 msintervals, the alerts may be alternated at 50 ms. Alternatively, theactive period 502 associated with a higher priority event, as determinedby the safety system, may be commanded more often. For example, if theforward alert is deemed to be more serious, the seat will generate apattern such as forward-forward-side-forward-forward-side. The patternmay be based on the individual system alert or may be customized in thecontext of a multiple alert scenario.

Examples of lengths of active and inactive periods of alert patterns areprovided below. A haptic alert for a Lane Departure Warning (LDW) eventmay be indicated by three pulses commanded with active periods of 80 msand inactive periods of 120 ms. A Rear Cross Traffic Alert (RCTA) eventmay be indicated by three pulses commanded with active periods of 100 msand inactive periods of 100 ms. A Forward Collision Alert (FCA),Collision Imminent Braking (CIB), or Adaptive Cruise Control (ACC) eventmay be indicated by five pulses commanded with active periods of 100 msand inactive periods of 100 ms. A Rear Park Assist (RPA) first detectevent may be indicated by one or two pulses commanded with activeperiods of 70 ms and inactive periods of 130 ms. A RPA and Front ParkAssist (FPA) near object event may be indicated by five pulses commandedwith active periods of 70 ms and inactive periods of 130 ms. An ACC “gonotifier” event (to signal to the driver using ACC, after the vehiclehas come to a stop, that the vehicle they are following has proceeded tomove forward) may be indicated by three pulses commanded with activeperiods of 100 ms and inactive periods of 100 ms. It should beappreciated that other relative and absolute time periods may beincorporated without departing from the scope of the present disclosure.

In various embodiments, the alert mode can indicate multiple alert modesat any one time (e.g., a Forward Collision Warning and Lane DepartureWarning may occur in close time proximity). In such a case, thedetermined alert patterns for one or more of the various alert modes canbe arbitrated to determine a preferred pattern, can be combined or addedto create unique, superimposed, and/or summative patterns without theneed for arbitration, and/or can be presented simultaneously without theneed for arbitration. In this latter case where arbitration is notneeded, if another alert (e.g., Forward Collision Warning) is requestedwhile an alert is being executed (e.g., Lane Departure Warning), forexample, a seat vibration alert can generate the required pattern (orwaveform) for each required actuator, and then sum the new pattern withthe remaining time of the currently executing pattern, and execute theresult for each required actuator. Active time and inactive time foreach actuator would be affected by the summation process, however thevibratory intensity during active time could be maintained (or increasedif desired) if more than one alert is requesting active time for thatmoment.

In operation 614 the controller generates a signal to command theselected pattern of haptic actuators, the selected number of activehaptic periods, and the duration of active and inactive haptic periods.For example, the controller 350 may generate the signal to command theactuators 322, 332 to provide the haptic pulses 512.

Referring now to FIG. 7, a flowchart for a method 700 of controlling ahaptic system is illustrated in accordance with some embodiments. Forexample, the controller 350 may generate a signal with active periods502 to command the actuators 322, 332 to create the pulses 514. Ingeneral, the method 700 establishes a constant vibration feel usingpulse width modulation (PWM) control of haptic actuators based on anactual battery voltage provided to a controller.

In operation 702, the controller selects a pattern of active hapticperiods during which the controller will command haptic pulses fromhaptic actuators. For example, the controller 350 may select a patternof active haptic periods 502 by performing the operations of the method600 described above.

In operation 704 the controller determines the desired intensity of thehaptic pulses. For example, the controller 350 may determine theintensity by retrieving the desired intensity from a lookup table. Inone example, the controller 350 may determine that the haptic pulses 512will be closely spaced with unique intensity values (e.g., “BUZZ-buzz”or “buzz-BUZZ,” where capitals indicate unique intensity values) tocreate unique pulse signatures.

The controller determines the desired voltage of a signal to begenerated during the active haptic periods to achieve the desiredintensity of the haptic pulses in operation 706. For example, thedesired voltage to apply to the motor 400 may be determined based on thedirectly proportional relationship between the rotational speed of thedirect current motor 400 and the voltage applied to the motor 400. Inone example, the controller 350 retrieves the desired intensity from alookup table and omits operation 704.

In operation 708, the controller determines the actual battery voltagesupplied to the controller. The actual battery voltage supplied invehicles may vary within and between ignition cycles. In one example,the controller 350 measures the actual voltage supplied to thecontroller 350 by the battery 12. The controller determines whether theactual voltage is within thresholds in operation 710. The thresholdsindicate a range of voltages near the desired voltage in which thecontroller will not modify the active periods. For example, when thedesired voltage is 11 volts and the actual supplied battery voltage is11.1 volts, the controller 350 may determine not to modify the activeperiods.

When the actual battery voltage is not within the thresholds, thecontroller calculates a pulse width modulation (PWM) pattern thatsimulates the desired voltage in operation 712. In general, a PWMpattern is a rapid sequence of “on” periods where voltage is provided tothe motor and “off” periods where no voltage is provided to the motor.

In operation 714, the controller generates a signal for the activehaptic periods based on the calculated PWM pattern. For example, the PWMpattern may be commanded to the motor 400 during the active period 502of the actuation profile 500 to control the power delivered to themotor. Because a DC motor speed is proportional to voltage, the PWMpattern creates consistent vibration intensity by simulating the desiredvoltage. For example, when the battery voltage is higher than desired,the proportion of “on” periods in the PWM pattern may be reduced.Additionally, the PWM pattern may be adjusted to create differentintensities of vibration. For example, to produce a vibration with ahigher intensity, the proportion of “on” periods in the PWM pattern maybe increased.

Referring now to FIG. 8, a flowchart for a method 800 of controlling ahaptic system is illustrated in accordance with some embodiments. Forexample, the controller 350 may generate a signal with active periods502 to command the actuators 322, 332 to create the pulses 512. Ingeneral, the method 800 establishes desirable vibration characteristicsfor a wide range of users so that adjustment control may be eliminatedor reduced. Furthermore, the method 800 may be utilized to achievedesirable high frequency motor characteristics, as will be discussedbelow.

In operation 802, the controller determines a standard vibrationintensity of haptic pulses based on a type of haptic alert. For example,the controller 350 may use a table lookup to determine the standardvibration intensity, or a continuous functional relationship. In oneexample, the standard vibration intensity is selected based on an“alerting and not yet annoying” detection level felt by users betweenthe lowest fifth percentile of people by size and the largest fifthpercentile of people by size.

The controller determines interior and exterior conditions of thevehicle in operation 804. The controller determines whether the vehicleconditions indicate that the vibration intensity is to be modified inoperation 806. When the vibration intensity is to be modified, thecontroller calculates adjustments to the active periods 502 to achieve amodified vibration intensity. For example, the controller 350 maycalculate a PWM pattern that will achieve the modified vibrationintensity.

In one example, the interior vehicle conditions include sensed orpredicted acoustics of the interior of the vehicle that may impact adriver's ability to sense the vibration. For example, the detection of aparticular song or music being played on the radio may be used to adaptthe alert pattern either by increasing the vibration intensity based onthe presence of low frequency content or radio volume. Other interiorconditions may include the output of a driver distraction module, drowsydriver module or enabled state of semi-autonomous driving systems (e.g.,cruise control, adaptive cruise control, lane keeping or lane centeringsystem).

The exterior vehicle conditions can include, but are not limited to,sensed or predicted acoustics or vibrations of the exterior of thevehicle that may impact the driver's ability to sense the vibration. Forexample, the detection of vehicle vibration as indicated by the vehiclesuspension system can be used to adapt the alert pattern during roughroad conditions. The pattern may be adjusted based on the nature ormagnitude of the vibration from the suspension system. For example, ifan average magnitude over a predetermined time is above a threshold, thealert pattern can be adjusted to increase the vibration intensity (e.g.,by a discrete value, or a value that is determined based on themagnitude).

The controller determines desirable active period profiles in operation812. For example, the leading edge 506 and trailing edge 508 of theactive period 502 may be tapered by incorporating a varying PWM patternto provide different haptic feedback profiles. For example, the PWMpattern may be adjusted to result in a haptic pulse 512 that has alinear or exponential increase in acceleration. Similarly, the endportion of the haptic pulse 512 may be varied by adjusting the PWMpattern. The rate of increasing acceleration in the haptic pulse 512 maybe used to indicate the severity of the alert. For example, a rapidlyincreasing haptic pulse 512 intensity indicates an imminent, near-fieldalert and a slowly increasing haptic pulse 512 intensity indicates afar-field, less critical alert.

The controller determines desirable high frequency characteristics inoperation 814. For example, the controller 350 may adjust the actuationprofile 500, the PWM pattern, and the motor characteristics to create adesired acceleration profile felt by variously sized drivers. In oneexample, a high frequency component of the vibration corresponding tothe rotational speed of the motor is within the range of 55 to 67 Hz.The high frequency component is also selected to reduce undesirableinteractions with road vibration frequencies (e.g., masking of theactuation vibration).

In operation 816, the controller calculates adjustments to the activeperiods to achieve the desired high frequency characteristics and hapticpulse profile. For example, the controller 350 may adjust the PWMpattern or on/off compensation patterns during the active periods 502.In general, the on/off compensation patterns stop commanding actuationof the haptic actuators when the haptic actuators exceed an upperthreshold rotational speed, and resume commanding actuation of thehaptic actuators when the rotational speed of the haptic actuators isless than a lower threshold.

While at least one exemplary embodiment has been presented in theforegoing detailed description, it should be appreciated that a vastnumber of variations exist. It should also be appreciated that theexemplary embodiment or exemplary embodiments are only examples, and arenot intended to limit the scope, applicability, or configuration of thedisclosure in any way. Rather, the foregoing detailed description willprovide those skilled in the art with a convenient road map forimplementing the exemplary embodiment or exemplary embodiments. Itshould be understood that various changes can be made in the functionand arrangement of elements without departing from the scope of thedisclosure as set forth in the appended claims and the legal equivalentsthereof.

1. A method, comprising: determining at least one of interior conditionsand exterior conditions of a vehicle that includes a plurality of hapticactuators disposed in a seat; calculating at least one of a pulse widthmodulation (PWM) pattern and an on/off compensation pattern based on thedetermined at least one of the interior conditions and the exteriorconditions; and generating a signal with active periods that include atleast one of the calculated patterns to command the plurality of hapticactuators to produce haptic pulses.
 2. The method of claim 1 whereindetermining at least one of the conditions includes determining theinterior conditions that include determining acoustics of the interiorof the vehicle.
 3. The method of claim 1 wherein determining at leastone of the conditions includes determining the exterior conditions thatinclude determining road vibration frequencies, and wherein calculatingat least one of the patterns further includes calculating at least oneof the patterns based on the road vibration frequencies.
 4. The methodof claim 3 wherein determining the road vibration frequencies includesdetermining whether an average magnitude of vibrations in a suspensionsystem is above a threshold.
 5. The method of claim 1 whereincalculating an on/off compensation pattern includes ceasing to commandactuation of the haptic actuators when the haptic actuators exceed anupper threshold rotational speed, and includes resuming command ofactuation of the haptic actuators when the rotational speed of thehaptic actuators is less than a lower threshold.
 6. The method of claim1 wherein calculating at least one of the patterns includes calculatingthe at least one of the patterns that generates haptic pulses with ahigh frequency component between about 55 Hz to about 67 Hz.
 7. Themethod of claim 1 wherein calculating at least one of the patternsincludes calculating the at least one of the patterns that generateshaptic pulses with a high frequency component between about 40 Hz andabout 80 Hz and a vertical acceleration of vibration normal to a bolsterof the seat between about 50 m/s² and about 72 m/s².
 8. The method ofclaim 1 further comprising calculating a taper for the active period tomodify an acceleration profile of the haptic pulses, and whereincalculating at least one of the patterns includes calculating at leastone of the patterns based on the taper.
 9. A method, comprising:determining at least one of interior conditions and exterior conditionsof a vehicle that includes a plurality of haptic actuators disposed in aseat; determining a high frequency component of haptic pulses to commandfrom the haptic actuators based on the determined at least one of theinterior conditions and the exterior conditions; calculating at leastone of a pulse width modulation (PWM) pattern and an on/off compensationpattern based on the at least one of the interior conditions and theexterior conditions to actuate the plurality of haptic actuators andgenerate haptic pulses with the high frequency component; and generatinga signal with active periods that include at least one of the calculatedpatterns to command the plurality of haptic actuators to produce thehaptic pulses.
 10. The method of claim 9 further comprising determiningroad vibration frequencies, and wherein calculating at least one of thepatterns further includes calculating at least one of the patterns basedon the road vibration frequencies.
 11. The method of claim 10 whereindetermining the road vibration frequencies includes determining whetheran average magnitude of vibration in a suspension system is above athreshold.
 12. The method of claim 9 wherein determining the interiorconditions includes determining acoustics of the interior of the vehiclethat may impact a driver's ability to sense the haptic pulses.
 13. Themethod of claim 9 wherein determining a high frequency component ofhaptic pulses to command further includes determining a high frequencycomponent that is between about 55 Hz and about 67 Hz and a verticalacceleration of vibration normal to a bolster of the seat between about50 m/s² and about 72 m/s².
 14. The method of claim 9 further comprisingcalculating a taper for the active period, and wherein calculating atleast one of the patterns includes calculating at least one of thepatterns based on the taper.
 15. A vehicle, comprising: a seat forsupporting a driver of the vehicle; a plurality of haptic actuatorsdisposed in the seat and configured to produce haptic pulses; and acontroller that: determines at least one of interior conditions andexterior conditions of the vehicle; calculates at least one of a pulsewidth modulation (PWM) pattern and an on/off compensation pattern basedon the at least one of the interior conditions and the exteriorconditions; and generates a signal with active periods that include theat least one of the calculated patterns to command the plurality ofhaptic actuators to produce the haptic pulses.
 16. The vehicle of claim15 wherein the controller further determines the interior conditionsthat include acoustics of the interior of the vehicle.
 17. The vehicleof claim 16 further including a suspension system, and wherein thecontroller determines whether an average magnitude of vibration of thesuspension system is above a threshold.
 18. The vehicle of claim 15wherein the controller calculates the at least one pattern thatgenerates haptic pulses with a high frequency component between about 40Hz and about 80 Hz and a vertical acceleration of vibration normal to abolster of the seat between about 50 m/s² and about 72 m/s²; and. 19.The vehicle of claim 15 wherein the controller calculates the at leastone pattern that generates haptic pulses with a high frequency componentbetween about 55 Hz to about 67 Hz.
 20. The vehicle of claim 15 whereinthe controller further calculates a taper for the active period edges,and wherein the controller calculates at least one of the patterns basedon the taper.